The First Food of the Common White-Fish. 
97 
more forcibly to the white-fish than to any other species in the 
lakes; because this is for several reasons the most important purely 
fresh-water fish of the great lake region, and proves to have a dis- 
tinctly different food when young from that upon which it is de- 
pendent later. 
According to the recent census report,'* more than twenty - 
one million pounds of white-fish were taken in the Great Lakes 
in 1879 , valued at over three-quarters of a million of dollars, and 
representing nearly half the total sum derived from the lake fish- 
eries of all kinds. These fisheries employ over five thousand men, 
and a fixed capital of one million three hundred and fory-six thou- 
sand dollars. When we reflect that this enormous drain upon the 
number of the species is necessarily, to a considerable extent, an 
addition to the natural tax levied upon it by its enemies other than 
man, we see that there must be an artificial supply provided, or 
the fisheries will gradually fail. 
The importance of the knowledge of the food of so valuable a 
species needs no demonstration, especially when we consider that, 
consistently with what has been said above, it may not be diffi- 
cult to overdo the work of propagation. 
If the white-fish were to be multiplied indefinitely, without any 
attention to the character or abundance of its food supply, it 
would soon reach such a number that it must infringe upon its 
own food capital, diminish the average number of the animals 
upon which it depends for subsistence, and so finally indirectly 
cripple itself. Then the money and labor expended in its culture 
would be principally lost, and the last state of the species would 
be worse than the first. An acquaintance with the food of the 
young is especially necessary, because they are planted by the 
fish-culturist when, having already absorbed the egg-sac (the sup- 
ply of food by which they are under natural conditions supported 
until they have time to scatter themselves widely through the 
water), they are in a peculiarly helpless condition, unable to wan- 
der far in search of subsistence, and compelled to find food 
speedily or perish. One would say, therefore, that their alimen- 
tary resources and habits should be well and thoroughly known, 
that the range, period and abundance of the organisms upon 
^'Census Bulletin No. 261, Sept. 1, 1881. 
